1. Technical Field of the Invention
The present invention relates working machines such as a hydraulic shovel, and among them, more particularly, to a working machine of a model in which gas is discharged through an exhaust opening formed in a floor wall portion that covers an engine room from a lower side.
2. Description of the Background Art
In general, in a working machine, an exhaust opening is formed in an upper wall portion or a rear wall portion that covers an engine room, and gas is discharged in a horizontal direction through the exhaust opening.
However, in this case, in a mini shovel or the like that has a driver's seat open to the surroundings, there is a problem in that since the driver's seat is disposed near an exhaust opening, the operator is likely to be influenced by the heat and the noise of exhaust gas.
Thus, in order to reduce the influence of the heat or the like of exhaust gas from reaching the driver's seat, a gas exhaust structure is proposed in which a distal end (tail pipe) of an exhaust pipe that blows exhaust gas is disposed inside an engine room and the exhaust gas is discharged through an exhaust opening formed in a floor wall portion disposed so as to cover the engine room from the lower side (for example, Japanese Patent Application Publication No. 2013-24078).
Specifically, a mini shovel of Japanese Patent Application Publication No. 2013-24078 includes a cylindrical duct extending in an up-down direction on a lateral side of an engine. This duct is configured to guide gas inside the engine room to the exhaust opening that is open on the lower side of the engine room. Further, a tail pipe is inserted in the duct.
Thus, the gas inside the engine room and the exhaust gas are mixed in the duct and the heat and the noise of the exhaust gas are reduced. After that, the mixture gas is discharged downward from the exhaust opening.
Although not described in Japanese Patent Application Publication No. 2013-24078, in a small working machine of a model such as a mini shovel, a number of members are densely disposed in the engine room. Due to this, there is practically no space margin inside the engine room.
In particular, since the space of the engine room on both sides of the engine is narrow, it is not easy to secure the space for disposing such a cylindrical duct as disclosed in Japanese Patent Application Publication No. 2013-24078.